Various methods are known in the art for securing or fixing the axial position and/or the amount of axial pre-loading of a machine element disposed, e.g., on a shaft or in a bore, so that the actual axial position and/or the actual axial pre-loading of the machine element does not unacceptably deviate from a desired axial position and/or a desired axial pre-loading. For example, an abutment device can be fixedly disposed adjacent to one axial side of the machine element and an abutment surface of the abutment device may be positioned so as to axially abut against the machine element, thereby preventing a change of the position of the machine element in an axial direction. In addition, if the abutment surface is forcibly pressed against the machine element along its axial direction such that a shifting or displacement of the machine element in the axial direction is prevented, a pre-loading or biasing or tensioning of the machine element in the axial direction can be produced.
For small machine elements having dimensions in the range of a few centimeters, the axial securing operation is normally performed during an automated mounting process that utilizes standard components. However, for very large machine elements, the absolute tolerances, in particular the tolerances of the installation space, can be relatively large values, such that an individualized alignment or adjustment may be necessary to axially secure or fix the machine element with defined properties, e.g., with a pre-defined axial pre-loading.
To overcome this tolerance problem, it is known, e.g., to fix a large bearing on a shaft by providing an axial support between a shaft shoulder and a clamping ring. A custom-made spacer ring is then disposed between the large bearing and the clamping ring in the axial direction in order to precisely compensate for the tolerances. However, if a customized production of the spacer ring is required or the selection of a suitable spacer ring from an assortment of spacer rings is necessary to precisely compensate the tolerances, significant additional expenses and/or labor requirements will incurred during the assembly process.
Such a tolerance compensating method can be used, e.g., when mounting a bearing of a rotor shaft in a wind turbine. In this case, the rotor shaft bearing abuts against a shaft shoulder on one axial side and is secured or fixed by a clamping ring on the other axial side. In addition, the clamping ring axially abuts against a further shaft shoulder or an axial end surface of the shaft and is screwed together with the shaft. Even though this approach leads to usable results, there is a need for alternative solutions due to the relatively large expense incurred during the mounting process.
In principle, it is also possible to press a clamping ring having a relatively long radial clamping surface onto the shaft and then to axially displace or slide the clamping ring until it has reached its intended position. This axial displacement step can be performed, e.g., by using a hydraulic nut, with which both the necessary force and the necessary precision can be achieved. The use of a hydraulic nut for mounting a ring body on a shaft and for removing the ring body from the shaft is known, e.g., from EP 0 878 271 A2. This hydraulic nut includes an annular piston that is disposed in an annular groove and forms a pressure chamber with the groove. In order to axially displace or shift the ring body, the pressure chamber is filled with pressurized hydraulic fluid, which pushes the piston outwardly.
However, the relatively long radial clamping surface necessary for achieving a reliable securing of the machine element without using screws leads to the possibility that relatively strong forces could develop. Consequently, there is a risk of damaging the shaft and/or the clamping ring when using such a mounting process.